"A major problem with a hangover is of dehydration, and by attempting to sweat it out, further dehydration occurs," he said, which can lead to feeling physically drained, fatigue, body aches, and nausea — even more so than after a heavy night of drinking on its own.

Also, the byproducts of breaking down alcohol in the body are excreted as a toxin in sweat, and the level is higher when dehydrated, leading to more cramps, strains, and even injuries.

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Mark Leyshon, the senior policy and research officer, at Alcohol Concern, told the Huffington Post that people who exercise more also tend to drink more alcohol because they feel they've "earned it."

"The reasons for this are not entirely clear, but may be tied up around ideas of masculinity and peer influences ('play hard, drink hard' attitudes), and notions that we've 'earned' the right to drink heavily after vigorous exercise or that we are immune from the negative effects of alcohol because we regularly exercise," he said.

But it could be a waste of time, he added, because being dehydrated makes your performance "pretty underwhelming." Alcohol can also have a negative effect on our coordination. So if you pick up heavy weights that you can't control as well as normal, you can end up hurting yourself.

"Most worryingly, drinking can increase the potential for unusual heart rhythms," Sarah Jarvis, Drinkaware's medical advisor, explained in the same article. "This is a risk which significantly increases during exercise up to two days after heavy alcohol consumption. This is because the activity itself already increases your heart rate and with a lot of alcohol in your system, you put extra stress on the organ."

So not only are you likely to be grumpy and lacking in energy, exercising on a hangover can actually be dangerous. According to experts, no amount of exercise can reduce how bad you feel, so you might as well rest, drink lots of water, and try again the next day.